There has been known a machine tool wherein high rigidity and high follow capability are sought by using two synchronized axis feeds, that is, tandem drive for a spindle head (Y-axis) or a table (Z-axis) on which a heavy load is imposed.
Further, as a five-axis machining center with a tool spindle tilt mechanism, there has been known one wherein a turn control axis is added in a tilt mechanical unit and wherein a tool spindle is turned by a built-in direct-drive motor.
Additionally, as one capable of not only moving a spindle head up and down but also turning the same, that using a link mechanism is disclosed in Patent document 1. This, as shown in FIGS. 2 and 3 thereof, is of the construction that two moving bodies 4, 5 driven up and down by servomotors 11, 11 are provided on a single fixed ball screw 9 to be spaced vertically, that a spindle head 2 is attached to one of the moving bodies 5 to be turnable by a rotary body 3, and that one end of the rotary body 3 to which the spindle head 2 is fixed is jointed to the other moving body 4 through a link 7.    Patent Document 1: Japanese unexamined, published patent